1. Field of the Invention
The present disclosure relates to a mechanically operated cell (MOC) switch, and more particularly, to a MOC switch of a vacuum circuit breaker, which is uniformly operated regardless of an insertion stroke (or an operation distance) of a push rod that operates a MOC switch of a vacuum circuit breaker.
2. Background of the Invention
In general, a vacuum circuit breaker is a circuit breaker installed in a high voltage electric power system to break a circuit to protect the electric power system in the event of a dangerous situation such as a short circuit, an overcurrent, and the like, and it is designed by utilizing excellent insulating performance and arc extinguishment capability in a vacuum state.
A vacuum circuit breaker is constructed in a distributing board in which various electric equipment is installed and managed to operate or control a power plant, an electric power substation, or the like, and in general, a vacuum circuit breaker is accommodated within a cradle fixed to a distributing board so as to be used. In a distributing board, a connected position in which a terminal of a circuit breaker is connected to a load terminal of a cradle to supply a voltage and a current and a test position in which the terminal of the circuit breaker is separated from the terminal of the cradle and only an operation of the circuit breaker is tested. In particular, a mechanically operated cell (MOC) switch indicating an ON/OFF state of a circuit breaker operation, so that when a vacuum circuit breaker is in the test position, operations (closing and opening (trip) operations) thereof is tested or checked, and when the circuit beaker is in the connected position, peripherals are operated or interlocking is implemented by using a contact output (ON or OFF) of the MOC switch to secure stability of the circuit breaker operation.
In other words, when the vacuum circuit breaker performs an ON/OFF operation in the connected position, the MOC switch is associated with the operation of the vacuum circuit breaker to indicate an operational state of the is circuit breaker or send a signal to a peripheral device to perform interlocking, or the like, while to performing an ON/OFF operation.
Referring to the related art illustrated in FIG. 1, the related art MOC switch 1 is installed on a bottom surface of a cradle of a switch box, and when a circuit breaker is in an OFF state, a contact b (present within an auxiliary switch 2 of the MOC switch 1) of the auxiliary switch 2 is closed to indicate that the circuit breaker is in the OFF state. When the circuit breaker is in the OFF state, a push rod 3, which is connected to a body of the circuit breaker and makes a vertical movement, is not in contact with a connection lever 4 as illustrated in FIG. 2. When the circuit breaker is in an ON state, the push rod 3 is moved downwardly to press the connection lever 4 as illustrated in FIG. 3. As the connection lever 4 is rotated to rotate the auxiliary switch 2 by 90 degrees, a contact ‘a’ within the auxiliary switch 2 is closed, indicating that the circuit breaker is in the ON state.
However, in the case of closing the circuit breaker, when a movement direction of the push rod 3 and the operational direction of the connection lever 4 are the same so an overrun stroke occurs due to an impulsive load during the closing operation, an operation stroke of the connection lever 4 may be increased to cause impact with a stop pin 6 to cause the components to be deformed. Conversely, when the stroke of the push rod 3 is short, an MOC contact output is not made, and thus, peripherals, which are supposed to be operated according to the contact output, may not be actuated. Also, when the circuit breaker is closed, sliding friction may be made between the push rod 3 and the connection lever 4 to make a loss of input energy.